Reactive flash sintering (RFS) has garnered significant interest because of the simultaneous synthesis/reaction and sintering of multicomponent ceramic materials. While electric fields demonstrably accelerate reaction kinetics during RFS, the reciprocal effect of reactions on flash sintering (FS) remains unknown. In this study, the role of the solid-state reaction in the onset of FS was investigated using Al₂O₃–Y₂O₃ and Al₂O₃–Y₃Al₅O₁₂ (YAG) as models. The results show that the onset temperature of FS of Al₂O₃–Y₂O₃ is 350 °C lower than that of Al₂O₃–YAG under a constant electric field of 1000 V/cm. This demonstrates that the solid-state reaction significantly reduces the onset temperature, likely by enhancing the electrical conductivity of the sample. Remarkably, Al₂O₃–YAG ceramic composites with fine eutectic structures were prepared by RFS-ed Al₂O₃–Y₂O₃ at a furnace temperature of 850 °C, which is far below the eutectic temperature. The resultant eutectic ceramics exhibited mechanical properties comparable to those of conventionally solidified counterparts. RFS is expected to be an energy-efficient and sustainable sintering technology to fabricate high-performance eutectic ceramics.

Field-assisted sintering technology has revolutionized material processing by integrating temperature, mechanical, electrical, and magnetic fields to achieve unprecedented densification efficiency and microstructural control. Recent advances in techniques such as hot oscillatory pressing, cold sintering, high/ultra-high pressure sintering, spark plasma sintering, ultrafast high-temperature sintering, and flash sintering have enabled the fabrication of previously unattainable materials, including ultrafine-grained ceramics, nanostructured composites, and functionally graded materials. These materials possess exceptional performances under extreme conditions, expanding applications in aerospace, electronics, energy, and biomedicine. However, the rapid development of these methods has exposed limitations in conventional sintering theory, particularly in describing mass transport and interface evolution under multi-physics coupling. This review systematically examines representative field-assisted sintering technologies and discusses their principles, equipment configurations, and application cases. By analyzing current challenges and opportunities, we aim to bridge fundamental understanding with industrial implementation, providing insights for the design and fabrication of next-generation high-performance materials.

In-situ nano-Al-O reinforced aluminum matrix composites are fabricated via the powder hot extrusion method, and their distinctive microstructural attributes are examined to ascertain their impact on the room temperature tensile properties of these composites. Microstructural observations and mechanical property evaluations are conducted utilizing advanced characterization techniques, including X-ray diffraction （XRD）, scanning electron microscopy （SEM）, and transmission electron microscopy （TEM）, alongside room temperature tensile testing. The findings reveal that numerous in-situ formed nano-Al-O structures are uniformly dispersed throughout the fine-grained aluminum matrix, with grain sizes approximately 500 nm. Some of these nanostructures exhibit strip-like morphologies, possessing an average width of 20 nm and length of 65 nm, while others display short rod-like morphologies, with an average width of 10 nm and length of 20 nm. Attributable to the reinforcing effect of the nano-Al-O structures, the room temperature yield strength and ultimate tensile strength of the aluminum matrix composites attain 402 MPa and 494 MPa, respectively, marking a significant increase of 2.90 times and 2.66 times compared to pure aluminum（103 MPa and 135 MPa, respectively）. Notably, these composites maintain ductile fracture characteristics.

In this study, a facile device was designed to generate stable plasma at room temperature using a low-voltage/current power source. The setup, which uses carbon felts as electrodes in air atmosphere, enables a novel plasma assisted sintering (PAS) technique to consolidate 3 mol% yttria-stabilized zirconia (3YSZ) ceramics at room temperature. The activation voltage required for plasma formation is positively correlated with the distance between the electrodes, with a minimum threshold as low as 50 V. Remarkably, the relative density of the PAS-treated 3YSZ ceramics reached 97.4% within 40 s under a voltage of 80 V and a current of 1.7 A. The electrical power dissipation profile and densification of the PAS-treated 3YSZ ceramics were analyzed in detail. The results confirmed that the rapid densification of 3YSZ ceramics arises not only from plasma-induced thermal effects, but also from the athermal effects caused by the current passing through the sample. This novel PAS technique is a promising low-cost and rapid method for preparing high-performance ceramic materials.

Zirconia has broad application prospects in the industry, but unlike metal materials, it is difficult to control the microstructure and improve mechanical properties of ceramics through post heat treatment. This article proposes a plasma treatment technique at room temperature and studies the effects of plasma treatment and applying current on the microstructure of ceramics, achieving grain size control of dense 3YSZ (3mol% yttria stabilized zirconia) ceramics. The results indicate that plasma treatment can promote the grain size of 3YSZ ceramics from submicron (0.45 μm) to tens of microns (>90 μm) in a short period of time. Applying current has a promoting effect on the rapid grain growth of ceramics. When the current is 1.0 A, the maximum grain size of zirconia can reach 255 μm, which is approximately 565 times larger than the initial grain size. The rapid grain growth caused by this plasma treatment can be attributed to the enrichment of oxygen vacancies induced by the electric field and the influence of plasma action on the rapid migration of grain boundaries. Compared with traditional heat treatment, plasma treatment technology has the advantages of high efficiency and low energy consumption, providing new ideas for ceramic microstructure control and single crystal material preparation.

Understanding the onset mechanism of flash sintering is essential for advancing electric-field-assisted sintering technologies. Herein, the onset temperature of flash sintering (FS) was examined for alumina–8 mol% yttria-stabilized zirconia (Al₂O₃–8YSZ) composites with varying molar ratios of Al₂O₃ and 8YSZ under an applied electric field of 900 V/cm. The results show a composition-dependent variation in the onset temperature, which can be divided into three different regions on the basis of the Al₂O₃ content, each reflecting a different onset mechanism. In region I (0–62.5 mol%), the flash sintering behavior is dominated by 8YSZ owing to the internal electrochemical reaction driven by the electric field. In region II (62.5–80 mol%), flash sintering is determined by the percolation networks of 8YSZ, which offer conduction paths for current. In region III (80–99 mol%), isolated 8YSZ particles catalyze the flash sintering of Al₂O₃ through interfacial dielectric breakdown. These results highlight a composition-dependent transition in the onset mechanism of flash sintering: Composites with low Al₂O₃ contents exhibit defect-dominated flash sintering associated with 8YSZ, whereas those with high Al₂O₃ contents follow a thermally controlled mechanism. Thus, Al₂O₃ and 8YSZ exhibit distinct onset mechanisms during flash sintering.

In this work, the onset mechanism of flash sintering (FS) of fully dense 8 mol% yttria-stabilized zirconia (8YSZ) was investigated. The conductivity behavior during the incubation stage was measured, which indicated that oxygen vacancy diffusion induced nonlinear conductivity in addition to Joule heating. When the blackening front was close to the anode, a flash event was triggered. The asymmetric temperature distribution along the sample was recorded during the full process; the highest temperature was located between the center point and the anode, and the cathode had the lowest temperature. We believe that the percolation mechanism with the contributions of oxygen vacancies and internal reactions dominated the onset process.

Room-temperature flash sintering (FS) for ceramics is a highly efficient and energy-saving new ceramic sintering technique. Addressing the current challenges in room-temperature flash sintering research, such as small product sizes, shape limitations, and high power requirements, limits their real application in the FS industry. In particular, for dog bone shape and small size, which are usually smaller than 10 mm, no records of sizes larger than 20 mm have been reported. In this study, a novel flash sintering device based on a composite layered carbon electrode structure was developed to conduct large-diameter sample flash sintering at room temperature (RT) in an air atmosphere under a direct current (DC) voltage below 100 V. Specifically, room-temperature flash sintering was achieved for ZnO ceramic disks with diameters of 40.0 mm and thicknesses of 1.80 mm, achieving a maximum relative density of 96.02%. Furthermore, room-temperature flash sintering was achieved for ZnO varistor ceramic disks with a diameter of 40.0 mm and a thickness of 1.93 mm, reaching a maximum relative density of 99.27%, a maximum voltage gradient of 330.5 V·mm⁻¹, and the highest nonlinearity coefficient (α) of 23.0. Room-temperature flash sintering was also achieved for 3 mol% yttrium-doped zirconia (3YSZ) ceramic disks, achieving a maximum relative density of 98.48%. The proposed flash sintering device and corresponding process demonstrate broad applicability for the ceramics industry.

it develops a new plasma assisted sintering (PAS) method to densify 3 mol% yttria stabilized zirconia (3YSZ) ceramics. The electrical curve characteristics and arc discharge phenomenon of PAS process were studied, and compared with other electric field assisted sintering methods. The influence of current density on the density, crystal structure, microstructure, and mechanical properties of 3YSZ ceramics was investigated. At a current density of 80 mA/mm², 3YSZ ceramics can achieve a relative density of up to 98.1% after 30 s of PAS, with a Vickers hardness of 15.1 ± 0.7 GPa, which is 2.3 GPa higher than that of samples prepared by conventional sintering. The effect of plasma also significantly changed the crystal structure characteristics of 3YSZ ceramics and obtained a gradient microstructure, proving that PAS is not a simple plasma heating process, and the current passing through the sample also has an important impact on the densification and grain growth. PAS has the characteristics of low initiate voltage, no need for pre-heating, short sintering time, and low energy consumption, which is expected to achieve low-cost and rapid densification of high-performance ceramic materials.

The development of supersonic aircraft has created an urgent demand for heat-resistant aluminum alloy that can serve at the temperatures range from 300 ℃ to 500 ℃. However, the high-temperature mechanical properties of heat-resistant aluminum alloys are still unable to meet practical application requirements. Therefore, further research is needed from the aspects of material composition design and microstructure control to improve the comprehensive mechanical properties of heat-resistant aluminum alloys. In this paper, the research progress of heat-resistant aluminum alloys is reviewed from the aspects of microalloying design and eutectic alloys, and the development trend of heat-resistant aluminum alloys is prospected. The article first systematically introduces the development history and research status of Al-Sc, Al-Cu, Al-Si, and Al-Mg heat-resistant aluminum alloys, focusing on the microalloying design ideas of heat-resistant aluminum alloys, as well as the effects of transition metal elements and rare earth elements on precipitation phases, microstructure, and mechanical properties. Subsequently, the development status of heat-resistant eutectic aluminum alloys in Al-Fe, Al-Ni, Al-Ce, and Al-Si systems is comprehensively summarized, with a focus on the important role of rapid solidification technology and additive manufacturing technology in promoting the development of heat-resistant eutectic aluminum alloys. Finally, the main problems faced in the development and application of new heat-resistant aluminum alloys are analyzed, and the development trends of future research on heat-resistant aluminum alloy is discussed from the perspectives of data-driven composition design, high-throughput experimental verification, engineering application research, and standard system construction.